Sanding floor pans Sucks

SEM makes weld through Epoxy primer in a can. Im going to use it on my engine bay.

Isn't that stuff like $35+ a can?? I know there are far better products out there rather than use weld-thru primer and much cheaper. Zinc aids in the prevention of rust but not well enough in my opinion. A catylized epoxy primer would be the best option imo. Once and done, never worry again.